C#

for (int i=menuItem1.MenuItems.Count - 1; i > 0; i++)
  menuItem1.MenuItems.RemoveAt(i);
 
// OR
 
for (int i=1; i < menuItem1.MenuItems.Count - 1; i++)
  menuItem1.MenuItems.RemoveAt(1);

protected override void WndProc(ref Message m)
{
  if (m.Msg != 0x020a) base.WndProc(ref m);
}

public delegate void SentHandler(object sender, SentArgs e);
public class Example
{
  public event SentEventHandler Sent;
  protected virtual void OnSent(SentEventArgs e)
  {
    if (Sent != null)
      Sent(this, e);
  }
  public void Send(string message)
  {
    // ...
    OnSent(new SentEventArgs(message));
  }
}
public class SentEventArgs : EventArgs
{
  string message;
  public SentEventArgs(string message)
  {
    this.message = message;
  }
  public string Message
  {
    get { return message; }
  }
}

public class Test
{
  static void Main()
  {
    Test t = new Test();
    t.A();
    t.B();
    t = new Test2();
    t.A();
    t.B();
    ((Test2)t).A();
    ((Test2)t).B();
  }
  public void A()
  {
    Console.WriteLine("Test.A");
  }
  public virtual void B()
  {
    Console.WriteLine("Test.B");
  }
}
public class Test2 : Test
{
  public new A()
  {
    Console.WriteLine("Test2.A");
  }
  public override void B()
  {
    Console.WriteLine("Test2.B");
  }
}

Test.A
Test.B
Test.A
Test2.B
Test2.A
Test2.B

public override bool PreProcessMessage(ref System.Windows.Forms.Message msg)
{
  Keys keyCode=(Keys)(int)msg.WParam & Keys.KeyCode;
  if((msg.Msg==WM_KEYDOWN || msg.Msg==WM_KEYUP) &&  keyCode==Keys.Enter) 
  {
      msg.WParam=(System.IntPtr)0;
      // Do stuff here
        return true;
  }
}

protected override bool ProcessDialogKey(Keys keyData)
{
  if (keyData == Keys.Enter)
  {
    SendKeys.Send("{TAB}"); // Quick and dirty way
  }
  return false; // Continue processing the key(s)
}